B.H.
I was diagnosed with Gestational Diabetes and my OB sent me to an Endocrinologist ASAP. They even called me to make sure I got an appointment within less than a week. At my first appointment I was also seen by a Dietitian, a RN, and a professional/certified Diabetes counselor. This team explained everything in detail from Dieting to exercise and possible complications etc.
She may also seek a high risk OB to be on the safe side. All in all I was told to yes, limit my carb consumption as such:
30 gr carbs for (B/fast)
15 grs ofcarbs (snack)
45 gr carbs Lunch
15 gr carbs afternoon snack (ei: a slice of 100 w/w bread with peanut butter) and a cup of tea or coffee "milk has carbs too so watch out"
and for some odd reason
60 grms of carbs for dinner.
Actually no, they explained that it is best to eat most carbs at night only while you are pregnant.
30 grs carbs (Snack before bed) I actually try not to have the snack before bed, cuz I am afraid my sugars will be super high in the am.
As usual consult your doctor to be certain that "this sample may work for you" We are all different and so your condition may be unique.
Good luck and tell her to go see and Endocrinologist and Dietitian like NOW!